How better science could help solve environmental justice problems

In the world of public health research and environmental monitoring, "cumulative impacts" are edging toward conventional wisdom--but at EPA headquarters, the phrase is just becoming hip. This week, the agency doled out $32 million dollars to study the health impacts of exposure to multiple pollutants at once. That's on top of the $7 million granted in January to study the cumulative impacts of chemical and non-chemical stressors on low-income and minority populations. This new sum will fund four research centers at the University of Washington, Michigan State University, Emory University, and Harvard University. The program at the University of Washington will hone in on toxic-blends of particulate matter, nitrogen oxides, and volatile organic compounds from automobile exhaust, which could elevate health risks among people living, working, or attending school near roadways.

For years, environmental justice advocates have pressured agencies and researchers to conduct better science by studying the cumulative impacts of chemicals, rather than the impact of a single toxin, on an individual's health. When mixed with other chemicals or compounded with social stressors such as poor diet or financial uncertainty, environmental toxins can often have an amplified health effect. In California, state agencies have already used cumulative impact data in regulatory decision making, suggesting "air buffers" around sites with hazardous emissions and considering pollution levels when deciding where to locate schools. In Los Angeles and San Diego, community groups are using the data to identify toxic hotspots and turn them into "green zones" by taxing high-emitters and inviting clean industry.

In my last post on the EPA's environmental justice efforts, I quoted community leaders who worry they're being "studied to death." If we're talking epidemiological studies, then that might be the case--studies linking chemical exposure to serious health problems, like cancer, not only take a tremendous amount of time and money, but they often require a larger sample size than a community can offer. "You end up seeing false negatives," says Rachel Morello-Frosch, associate professor of public health at the University of California, Berkeley. "You have to conclude that there's no significant correlation, when it could just be a sampling error. It's a huge source of frustration for everyone, scientists and communities alike."

Many communities are beginning to understand that epidemiology is a blunt tool when it comes to identifying and solving environmental justice problems. When Morello-Frosch receives calls from a community organizer asking her to study the impact of a chemical on his or her neighborhood's health, she has to ask, "Is the study really going to answer the question you're asking in the time you need it answered?" Then she adds, "And what if our results are inconclusive?"

But cumulative impact research, as opposed to traditional chemical effect studies, could be quite helpful in rapidly catching and treating environmental justice problems. If researchers understand how certain chemical and social factors interact to affect health, then agencies, doctors, and advocacy groups can identify communities at risk and intervene with treatment or regulatory action. The science of pollution exposure could become a powerful tool to prove a problem exists. But then it's still up to state or federal agencies to take regulatory action, and industry to comply.